Comment by chriskottom

I wouldn't claim to be any kind of expert, but the advice you need to hear right now is: start. Write about what matters to you. Don't wait to come up with a coherent thesis or mission statement about what your blog is before you've written the first post. If you start writing regularly, you'll find what you care abut and what resonates with others, and that's the sweet spot where an audience can potentially be found.